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HARVARD  HEALTH  TALKS 

THE  CARE  AND  FEEDING  OF 

CHILDREN 

BY  JOHN  LOVETT  MORSE 

PRESERVATIVES  AND  OTHER 

CHEMICALS  IN  FOODS:   THEHl  USE 

AND  ABUSE 

BY  OTTO  FOLIN 

THE  CARE  OF  THE  SKIN 
BY  CHARLES  JAMES  WHITE 

THE  CARE  OF  THE  SICK  ROOM 
BY  ELBRIDGE  GERRY  CUTLER 

THE  CARE  OF  THE  TEETH 
BY  CHARLES  ALBERT  BRACKETT 


HARVARD  HEALTH  TALKS 


- 


HARVARD  HEALTH  TALKS 


THE  CARE  OF  THE  TEETH 


BY 

CHARLES  A.  BRACKETT,  D.M.D. 

PROFESSOR  OP  DENTAL  PATHOLOGY  IN 
HARVARD  UNIVERSITY 


1  wd  iiiii!;' 


^ip^ 


CAMBRIDGE 

HARVARD  UNIVERSITY  PRESS 

1915 


COPYRIGHT,  1915 
HARVARD  UNIVERSITY 


S>7TL 


HARVARD  HEALTH  TALKS 

PRESENTING  the  substance  of  some 
of  the  public  lectures  delivered  at 
the  Medical  School  of  Harvard  Univer- 
sity, this  series  aims  to  provide  in  easily 
accessible  form  modern  and  authorita- 
tive information  on  medical  subjects 
of  general  importance.  The  following 
committee,  composed  of  members  of 
the  Faculty  of  Medicine,  has  editorial 
supervision  of  the  volumes  published : 

EDWARD  HICKllNG  BRADFORD, 
A.M.,  M.D.,  Dean  of  the  Faculty  of 
Medicine,  and  Professor  of  Orthopedic 
Surgery,  Emeritus. 

HAROLD  CLARENCE  ERNST,  A.M., 
M.D.,  Professor  of  Bacteriology. 

WALTER  BRADFORD  CANNON,  A.M., 
M.D.,  George  Higginson  Professor  of 
Physiology. 


THE  CARE  OF  THE  TEETH 


THE   CARE  OF  THE  TEETH 

THE  importance  of  this  subject  needs 
no  argument.  Symmetrical,  sound, 
well-kept  teeth  are  important  contri- 
butions to  the  beauty  of  the  human 
countenance.  Their  possession  is  right- 
ly construed  to  mean  cultivation  and 
refinement.  A  person  with  nicely  kept 
teeth  may  be  expected  to  be  of  the 
kind  fastidious  in  other  particulars. 
Then  in  addition  to  the  beauty  of  the 
teeth,  may  be  urged  their  importance  in 
the  preparation  of  the  food  for  digestion 
and  assimilation.  All  other  things  being 
equal,  the  person  who  masticates  his  food 
thoroughly  is  the  person  likely  to  be 
blessed  with  the  most  comfortable  and 
complete  digestion,  and  the  best  nutri- 
tion. 

While  it  is  true  that  the  prosthetic 
dentist  is  able  to  provide  excellent  sub- 


HARVARD  HEALTH  TALKS 

stitutes  for  the  natural  teeth  when  these 
have  been  lost,  they  are  not  like  the 
teeth  which  nature  makes.  In  a  sense 
they  are  comparable  to  the  artificial  con- 
trivances with  which  we  replace  natural 
limbs.  They  are  an  added  care.  In  many 
mouths  it  is  not  possible  to  give  them 
a  good  fixation;  and  their  efficiency 
in  mastication  is  much  less  than  that 
of  natural  teeth. 

An  important  circumstance  with  ref- 
erence to  the  possession  of  good  teeth  is 
hereditary  influence.  The  laws  of  trans- 
mission from  parent  to  child  which  ob- 
tain in  other  particulars  exercise  their 
influence  upon  the  characteristics  of  the 
teeth.  Children  that  are  born  of  parents 
with  poor,  soft,  rapidly-decaying  teeth 
are  likely  to  inherit  similar  dental  pecu- 
liarities. Conversely,  children  born  of 
good  parentage,  whose  teeth  have  been 
regular,  little  inclined  to  decay,  and  gen- 
erally strong,  are  likely  to  possess  teeth 
resembling  those  of  their  parents. 
10 


CARE  OF  THE  TEETH 

Next  after  the  matter  of  heredity  are  the 
circumstances  surrounding  the  early  life 
of  the  child.  This  is  true  with  reference 
to  the  child's  entire  environment,  —  its 
home  life,  its  fresh  air,  its  outdoor  exercise, 
its  sleep,  and  especially  its  diet.  If  these 
particulars  of  the  home  life  are  wisely 
controlled,  the  teeth  of  the  children  share 
in  the  benefits.  If  there  is  ignorance  and 
a  lack  of  proper  regard  for  these  things, 
and  especially  if  such  ignorance  is  added 
to  a  bad  heredity,  it  is  only  natural  that 
we  should  find,  as  jve  do  find,  that  the 
teeth  of  the  children  are  poor,  soft,  in- 
clined to  decay  and  apt  to  be  lost  early. 

I  had  these  facts  forcibly  impressed 
upon  me  through  having  been  for  a  time 
in  my  early  studies  in  dentistry  in  a 
manufacturing  city  in  Massachusetts, 
having  a  population  including  many  not 
of  the  most  favored  class.  A  great  num- 
ber of  the  parents  were  of  foreign  birth, 
and  the  ancestry  of  the  children  was 
often  mixed.  The  homes  in  which  they 
11 


HARVARD  HEALTH  TALKS 

lived,  and  the  general  circumstances  of 
their  lives,  were  unfavorable.  A  con- 
siderable portion  of  their  diet  was  made 
up  of  a  poor  quality  of  baker's  bread  and 
molasses,  a  combination  not  only  lacking 
in  nutritional  elements  important  for  the 
teeth,  but  also  readily  fermentable;  and 
the  products  of  this  fermentation  are  es- 
pecially harmful  to  the  teeth,  as  we  shall 
see  a  little  later.  Among  those  children, 
I  have  many  times  seen  the  teeth  of  the 
temporary  set  at  the  age  of  four  years 
little  more  than  a  mass  of  decaying  roots 
in  suppurating  gums,  —  a  deplorable 
condition,  in  every  particular,  for  the 
child's  well-being. 

From  this  manufacturing  city  I  went 
to  begin  the  practice  of  dentistry  in  the 
place  which  has  since  been  my  home,  — 
a  residential  city  including,  particularly 
in  the  summer,  many  who  possess  in 
large  measure  what  are  usually  called  the 
advantages  of  life.  In  this  community 
I  came  immediately  and  directly  in  con- 
12 


CARE  OF  THE  TEETH 

tact  with  a  class  of  people  diametrically 
opposite  to  that  which  I  have  just  de- 
scribed. They  were  people  whose  stock 
was  vouched  for  by  that  distinguished 
success  in  life  which  gave  them  their 
accumulated  large  means,  with  its  asso- 
ciated cultivation.  In  these  families 
the  homes  of  the  children,  the  regimen 
under  which  they  were  brought  up,  the 
food  which  they  had,  the  fresh  air,  out- 
door exercise  and  the  abundance  of  sleep 
which  were  provided  for  them,  had  their 
legitimate  consequences  in  a  quality  of 
teeth  and  a  healtK  of  mouth  the  very 
opposite  of  those  which  I  had  seen  in  the 
other  city.  The  result,  in  each  instance, 
was  but  the  natural  consequence  of  the 
operation  of  influential  causes. 

Perhaps  I  can  best  speak  next  of  the  care 
of  children's  teeth,  of  the  reasons  why 
children's  teeth  should  have  good  care, 
and  of  how  that  care  should  be  given. 


is 


HARVARD  HEALTH  TALKS 

It  is  essential  for  a  child's  well-being 
that  its  first  teeth  be  in  a  state  of  com- 
fort and  serviceableness,  and  that  they 
be  retained  in  their  places  until  the  per- 
manent teeth  are  ready  to  succeed  them. 
If  a  child  has  open,  sensitive  cavities  in 
its  teeth,  they  are  a  source  of  suffering, 
of  discomfort  and  incapacity  in  chewing; 
and  if  these  cavities  are  permitted  to  pro- 
gress until  there  are  exposed  pulps,  there 
is  ordinarily  pain,  from  which  the  child 
may  suffer  extremely,  and  which,  espe- 
cially when  occurring  at  night,  will  be 
a  marked  source  of  disquietude  in  the 
family.  Then  if  the  child,  on  account  of 
neglect  of  its  teeth,  and  the  development 
of  penetrating  caries  with  its  associated 
pain,  prematurely  loses  teeth,  especially 
any  of  the  back  teeth  of  the  temporary 
set,  there  is  very  likely  to  be  irregularity 
in  the  permanent  set  as  a  result. 

The  teeth  of  the  child,  the  temporary 
teeth,  are  ordinarily  in  their  place  at  the 
age  of  three  years.    Contrary  to  the  ideas 


CARE  OF  THE  TEETH 

generally  held  among  parents,  none  of 
these  teeth  fall  out  until  nature  has 
brought  into  their  places  the  four  largest 
and  strongest  teeth  of  the  permanent  set. 
The  child's  set  of  teeth  is  twenty  in 
number,  ten  in  each  jaw,  five  in  each 
quarter  of  the  mouth.  The  first  teeth  of 
the  permanent  set  to  appear  are  almost 
invariably  in  place,  in  a  position  imme- 
diately behind  the  farthest  back  teeth 
of  the  child's  set,  at  the  age  of  six  years. 
These  established,  nature  replaces  one  of 
the  five  temporary  teeth  in  each  quarter 
of  the  mouth  each^ear  in  this  order :  — 
the  central  incisor  at  the  age  of  seven ; 
the  lateral  incisor  at  eight;  the  first  per- 
manent bicuspid  succeeds  the  temporary 
first  molar  at  nine;  and  the  second  bi- 
cuspid, the  second  temporary  molar  at 
ten;  and  the  cuspids  are  changed  at  the 
age  of  eleven.  These  are  approximate 
ages  with,  of  course,  some  considerable 
variation  in  the  cases  of  different  indi- 
viduals.    The  second  permanent  molar 

15 


HARVARD  HEALTH  TALKS 

appears  at  about  the  age  of  twelve,  and 
the  third  molar,  or  wisdom  tooth,  at  six- 
teen or  at  any  time  thereafter. 

Bearing  in  mind  what  I  have  said  of 
the  appearance  of  the  first  permanent 
molar  at  the  age  of  six,  while  the  tooth 
which  comes  into  place  immediately  for- 
ward of  it,  replacing  the  temporary  sec- 
ond molar,  is  not  due  until  the  age  of  ten, 
and  remembering  the  fact  that  any  tooth 
in  the  back  of  the  mouth  has  a  marked 
disposition  to  move  forward  if  there  is 
any  opportunity  for  such  motion,  it  fol- 
lows that  if  the  temporary  second  molar 
is  prematurely  lost  the  six  year  molar 
moves  forward  into  the  space  rightfully 
belonging  to  the  second  bicuspid,  so  that 
when  the  second  bicuspid  is  ready  to 
appear  four  years  later,  the  room  to 
which  it  is  rightfully  entitled  has  been 
largely  appropriated  by  the  six  year  mo- 
lar. This  leads  to  a  crowding  and  irregu- 
larity of  the  teeth  about  the  front  of  the 
mouth  which  is  deplorable.    Irregularity 

16 


CARE  OF  THE  TEETH 

of  the  teeth  is  a  thing  to  be  regretted,  not 
only  on  account  of  its  unsightliness,  but 
because  it  facilitates  the  inception  of 
several  diseases  destructive  to  teeth. 
Nowadays  instead  of  "  irregularity  "  of 
the  teeth  dentists  prefer  the  term,  mal- 
occlusion. This  takes  cognizance  of  the 
fact  that  the  right  relations  to  each  other 
of  the  teeth  in  the  opposing  jaws  is  of 
material  consequence  for  the  proper  per- 
formance of  the  function  of  mastication. 
If  at  the  time  of  eruption  the  teeth  do 
not  come  into  then;  right  relationships 
with  each  other  it  is  desirable  that  the 
dentist's  aid  be  sought  early.  There  is 
among  those  who  make  a  specialty  of 
correcting  malocclusion,  orthodontists 
as  they  are  called,  a  consensus  of  opinion 
that  it  is  better  to  make  teeth  grow  into 
their  right  positions  than  it  is  to  under- 
take to  put  them  there  after  they  have 
been  for  a  considerable  time  in  wrong 
relations.  The  orthodontists  also  hold 
as    cardinal    doctrine    that,    with    rare 

17 


HARVARD  HEALTH  TALKS 

exceptions,  all  of  the  teeth  should  be 
preserved;  in  other  words,  that  no  teeth 
should  be  extracted  "to  make  room,"  and 
that  the  dentist  should  not  undertake 
to  improve  upon  nature's  normal  type. 

A  related  matter  of  supreme  conse- 
quence is  the  condition  of  the  child's 
throat.  Throat  obstructions  of  every 
kind,  such  as  enlarged  tonsils  and  ade- 
noid growths,  especially  the  latter,  are  a 
serious  interference  with  the  child's  well- 
being,  physically,  mentally,  and,  as  is 
now  believed,  morally.  They  often 
cause  mouth-breathing;  and  with  all  the 
rest  of  their  mischievous  influence  have 
much  to  do  in  making  deformities  in  the 
face  and  jaws  and  in  the  positions  of  the 
teeth.  Orthodontists,  with  other  special- 
ists, insist  that  children's  throats  should 
be  made  clear.  Doing  this  contributes 
vastly  to  their  health  in  many  ways. 

To  the  conditions  mentioned  should  be 
added  an  important  fact  with  reference 

18 


CARE  OF  THE  TEETH 

to  the  development  of  teeth,  applying 
also  to  development  generally,  —  that 
precocity  ordinarily  means  a  poor  quality 
of  development,  while  tardiness  in  the 
development  and  eruption  of  teeth  has 
usually  associated  with  it  excellent  qual- 
ity. It  happens  in  a  few  instances  that  a 
baby  is  born  with  one  or  two  teeth  in 
sight,  and  that  it  follows  up  this  charac- 
teristic of  premature  development  in  all 
of  its  dentition.  Such  teeth  are  almost 
invariably  of  poor  quality  and  much  in- 
clined to  decay.  Nature's  capacity  for 
building  at  the  time  these  teeth  were 
prematurely  formed  was  so  limited  that 
she  could  not  do  her  best  work.  On  the 
other  hand,  teeth  that  are  tardily  formed 
and  tardily  erupted  are,  as  I  have  said, 
usually  strong  and  resistant. 

In  order  that  we  understand  something 
of  the  philosophy  of  the  good  care  of  the 
teeth,  it  is  desirable  that  we  know  some- 
thing of  their  constitution,  their  make- 

19 


HARVARD  HEALTH  TALKS 

up.  The  teeth  are,  in  a  sense,  dermal 
structures;  that  is,  like  the  hair  and  the 
nails,  they  might  without  much  stretch- 
ing of  the  fact  be  called  modified  skin. 
The  mucous  membrane,  which  lines  all 
of  the  orifices  of  the  body  and  is  reflected 
upon  a  considerable  portion  of  the  inte- 
rior chambers  and  passages,  is  but  a 
modified  skin,  an  internal  skin,  it  might 
be  called.  Histologically,  skin  and  mu- 
cous membrane  are  practically  identical. 
They  are  each  made  up  of  epithelial  cells, 
and  the  differences  between  skin  and 
mucous  membrane  are  differences  made 
by  differences  of  environment.  The  skin 
is  exposed  to  the  air,  accustomed  to  fric- 
tion, has  ordinarily  a  dry  surface,  while 
the  mucous  membrane  is  more  or  less 
protected  from  atmospheric  action  and 
does  not  receive  the  dry  friction  to  which 
the  skin  is  accustomed.  This  fact  is 
shown  in  a  sense  in  the  interchanged 
characteristics  of  skin  and  mucous  mem- 
brane, if  either,  through  any  abnormality, 
20 


CARE  OF  THE  TEETH 

becomes  subjected  to  the  environment 
of  the  other.  We  shall  see  a  little  later 
a  significance  of  this  skin-origin,  if  we 
may  call  it  so,  of  the  teeth. 

The  teeth  are  developed  in  an  invo- 
luted pocket,  or  cul-de-sac,  of  mucous 
membrane.  At  first  all  of  that  which  is 
to  become  tooth  is  made  up  of  soft  tissue 
so  invested.  Without  going  into  the 
minutiae  of  tooth  development,  we  may 
accept  the  fact  that  the  hard  tissues  of 
the  teeth  are  constructed  by  a  process 
of  calcification,  or  in  other  words,  by  the 
deposition  of  lime  salts  in  this  matrix 
of  soft  tissue  which  had  preceded.  The 
cells  that  are  the  actual  builders  of 
the  dentine  are  called  the  ondontoblasts. 
The  development  of  what  is  spoken  of 
by  dentists  as  the  dentine,  the  bone  of 
the  tooth,  begins  upon  the  periphery 
of  the  organ  of  formation,  and  proceeds 
progressively  from  without  inwards.  A 
cross  section  of  dentine  is  like  the  cross 
section  of  a  tubular  boiler.  It  is  made 
21 


HARVARD  HEALTH  TALKS 

up  of  a  multitude  of  microscopically  fine 
tubules  having  a  packing  of  what  is 
called  the  intertubular  substance,  and 
containing  something  which  has  the 
capacity  of  conveying  sensation.  The 
most  powerful  microscopes  which  have 
ever  been  made  are  unable  to  demon- 
strate the  penetration  to  any  consider- 
able distance,  except  in  rare  instances, 
of  nerve  tissue  into  the  dentinal  tubules; 
but  all  who  have  had  a  sensitive  cavity 
prepared  for  filling  will  testify  that  some- 
thing exists  in  the  constitution  of  the 
dentine,  which  has  a  lively  capacity  for 
conveying  sensation.  This  construction 
of  dentine,  while  it  is  largely  completed 
by  the  time  the  tooth  has  fully  erupted, 
attaining  its  place  among  its  fellows  in 
the  jaw,  continues  to  go  on  slowly 
through  life. 

That  which  is  spoken  of  commonly  as 
the  nerve  of  the  tooth  is  made  up  partly 
of  nervous  tissue,  but  it  includes  also 
arterial  and  venous  capillaries  for  the 

22 


CARE  OF  THE  TEETH 

nutrition  of  the  parts,  with  connective 
tissue  as  a  packing  material.  Inasmuch 
as  but  a  portion  of  this  substance  is 
nerve,  it  is  more  accurate  to  speak  of 
it  as  the  pulp  of  the  tooth.  From  what 
we  have  just  seen,  the  pulp  was  origi- 
nally as  large  as  the  completed  tooth, 
minus  the  enamel,  and  the  cementum 
which  covers  the  root;  and  what  is  usu- 
ally spoken  of  as  the  nerve,  or  as  we 
say,  the  pulp,  is  but  the  remains  of  the 
formative  organ,  and  is  the  main  de- 
pendence of  the  formed  tooth  for  its 
nutrition  continuously  through  life.  It 
grows  somewhat  smaller  through  addi- 
tional calcification  about  the  periphery. 
In  people  of  advanced  age  the  pulp 
becomes  extremely  attenuated,  almost 
obliterated. 

The  enamel  of  the  tooth  begins  to  form 
at  the  same  place  where  the  formation  of 
dentine  commenced,  and  goes  on  pro- 
gressively from  within  outwards,  so  that 
the  construction  of  enamel  is  finished  at 

23 


HARVARD  HEALTH  TALKS 

the  surface.  A  cross  section  of  enamel 
reveals  a  construction  of  six-sided  prisms 
of  great  resisting  capacity  when  the  for- 
mation is  perfect.  As  a  matter  of  fact 
this  construction  of  enamel  is  imperfect 
in  multitudes  of  instances.  Calcification 
of  enamel  begins  on  the  prominent  parts 
of  the  teeth  crowns,  the  cutting  edges  of 
the  incisors,  the  points  of  the  cuspids 
and  bicuspids,  and  the  eminences  of  the 
molars.  In  the  bicuspids  and  molars  it 
progresses  from  the  eminences  laterally 
down  into  the  valleys,  the  sulci  of  the 
teeth,  and  there  is  supposed  to  unite 
so  completely  as  to  form  an  unbroken 
sheet  of  enamel  over  the  entire  crown. 
If  the  formation  is  perfect,  this  is  what 
has  taken  place;  but,  as  I  said,  in  multi- 
tudes of  instances,  the  enamel  formed 
from  these  different  centers  fails  to  co- 
alesce at  what  should  have  been  the 
point  of  union,  and  there  remains  a  fis- 
sure or  seam  of  imperfect  construc- 
tion. 

24 


CARE  OF  THE  TEETH 

Now  as  we  are  studying  the  matter  of 
preservation  of  the  teeth,  we  need  to  get 
an  understanding  of  what  are  the  great- 
est dangers  to  which  the  teeth  are  ex- 
posed. These  dangers  are  principally 
two:  first,  dental  caries,  what  is  popu- 
larly known  as  decay  of  the  teeth;  and 
second,  diseases  of  the  investments  of 
the  teeth,  by  which  teeth  in  themselves 
often  intrinsically  good,  are  lost. 

In  the  first  place,  with  reference  to 
dental  caries,  a  disease  of  universal  prev- 
alence so  far  as  civilized  people  are  con- 
cerned, and  familiar  to  every  one  of  us. 
The  matter  of  causation  was  studied 
through  the  lives  of  many  generations 
of  men  without  the  attainment  of  any- 
thing like  full  and  positive  knowledge 
upon  the  subject.  As  in  the  investiga- 
tion of  many  other  things  which  have 
been  for  a  time  uncertain,  knowledge  has 
been  gained  step  by  step,  until  within 
the  last  quarter  of  a  century  we  have 
come  to  what  is  practically  a  full  under- 

25 


HARVARD  HEALTH  TALKS 

standing  of  what  are  the  influences  that 
occasion  the  decay  of  teeth. 

We  have  seen  that  the  hard  tissues  of 
the  teeth  are  made  up  principally  of  salts 
of  lime,  largely  the  carbonate  and  phos- 
phate of  lime.  This  means  that  they  are 
susceptible  to  the  influence  of  chemical 
action  that  may  attack  constructions  of 
salts  of  lime,  or  in  other  words,  they  are 
susceptible  to  the  action  of  acids,  and 
may  be  destroyed  by  such  action.  In- 
deed, a  French  investigator,  the  late 
Doctor  E.  Magi  tot,  as  the  result  of  a 
good  many  experiments  which  he  insti- 
tuted, arrived  at  the  conclusion  that  den- 
tal caries  was  a  purely  chemical  solution 
of  the  lime  salts  of  the  teeth  in  acids. 
But  there  was  a  fallacy  in  Magitot's 
conclusions  for  the  reason  that  in  his 
experiments  he  did  not  duplicate  condi- 
tions as  they  exist  in  the  mouth.  He 
did  produce  disintegration  of  enamel  and 
dentine  by  the  action  of  acids;  but  that 
is  not  dental  caries  as  it  exists  under 

26 


CARE  OF  THE  TEETH 

natural  conditions.  To  grasp  the  whole 
etiology  of  dental  caries,  we  need  to  take 
cognizance  of  the  constant  and  practic- 
ally inevitable  presence  of  multitudes  of 
microorganisms  in  the  tooth  environ- 
ment. The  mouth  is  an  ideal  culture 
chamber,  —  in  its  temperature,  in  it's 
moisture,  in  its  abundance  of  acceptable 
nutrition,  and  in  all  the  environment 
which  it  provides  for  germ  life.  These 
microorganisms  are  of  many  varieties. 
For  our  present  purpose,  we  may  speak 
especially  of  those  which  have  a  capacity 
for  the  induction  of  fermentation.  As 
you  doubtless  know,  ordinary  fermenta- 
tion is  inevitably  dependent  upon  the 
presence  and  the  life  activities  of  micro- 
organisms of  certain  types.  Without  the 
presence  of  these  microorganisms,  no  fer- 
mentation of  this  kind  is  possible.  These 
are  truths  that  in  their  practical  mani- 
festations and  demonstrations  are  more 
or  less  familiar  to  all  of  us,  —  perhaps 
prominently  so  in  the  fermentation  or 

27 


HARVARD  HEALTH  TALKS 

souring  of  certain  articles  of  food,  as  for 
instance  milk,  and  fruits  and  vegetables 
of  various  kinds.  Advantage  is  taken  of 
this  knowledge  of  the  function  of  micro- 
organisms in  inducing  fermentation  of 
different  substances,  to  counteract,  by 
various  expedients,  the  operation  of 
microorganisms,  as  for  instance,  by 
heating  to  a  germicidal  temperature  a 
substance  that  is  to  be  preserved,  with 
or  without  the  addition  of  sugar  or 
other  agencies  that  have  the  quality  of 
preserving  the  substances.  If  any  food 
material  be  absolutely  sterilized  in  its 
fresh  and  wholesome  condition  and  then 
be  sealed  from  contact  with  micro- 
organisms, its  preservation,  practically 
unchanged,  is  a  thing  accomplished  for 
indefinite  time.  Familiar  examples  of 
fermentation  are  the  fermentation  of 
wine,  of  beer,  of  cider.  As  you  know, 
there  are  various  and  successive  kinds  of 
fermentations  to  which  such  products 


28 


CARE  OF  THE  TEETH 

are  subject,  each  bringing  about  its  own 
type  of  change. 

Bear  in  mind  that  in  that  class  of  fer- 
mentations with  which  we  are  now  con- 
cerned, a  factor  prominent  in  the  results 
of  fermentation  is  the  formation  of  acid. 
This  is  shown  by  the  at  least  partially 
synonymous  use  of  the  term  "  souring  " 
for  fermentation.  We  say  that  the  apple- 
sauce has  fermented,  or  has  soured;  and 
everybody  understands. 

Wherever  life  exists  something  is  con- 
sumed, something  is  transformed;  some- 
thing which  is  aAvaste  product  for  the 
organism  first  concerned  is  developed. 
And  this  waste  product  is  often  of  far 
more  consequence  as  a  disease  producer 
than  the  microorganisms  themselves.  In 
other  words,  in  many  cases  it  is  the  pto- 
maines that  induce  the  disease,  as  it  is 
the  microorganisms  that  produce  the  pto- 
maines. This  indirect  mischief -making 
of  the  microorganisms  obtains  to  a  large 
extent  in  tooth  diseases,  as  we  shall  see. 

29 


HARVARD   HEALTH  TALKS 

Perhaps  some  people  still  hold  to  the 
supposition  that  the  microorganisms  pro- 
ducing these  changes,  particularly  the 
changes  in  the  mouth,  are  animal  para- 
sites, that  is,  that  they  are  in  themselves 
minute  animals.  This  is  an  error.  Al- 
though we  may  sometimes  jokingly 
speak  of  the  "  bugs  "  in  the  mouth  they 
are  not  "  bugs."  With  extremely  few 
exceptions  the  disease-producing  micro- 
organisms flourishing  in  the  mouth  and 
in  the  other  regions  of  the  body  are  be- 
lieved to  be  in  their  nature  and  constitu- 
tion vegetable  and  not  animal.  They 
are  a  particularly  simple  and  minute 
form  of  vegetable  life,  and  they  may  be 
compared  to  some  of  the  other  low  forms 
of  vegetable  life  plainly  apparent  to  the 
ordinary  senses,  such  as  lichens  and 
mosses.  Just  as  we  may  see  patches  of 
moss  growing  upon  a  ledge  of  rock,  parti- 
cularly in  a  damp  place  and  upon  a  stone 
surface  not  exposed  to  much  friction,  we 
find  that  these  microorganisms  of  the 

30 


CARE   OF  THE  TEETH 

mouth  have  a  capacity  of  forming  among 
themselves  colonies  of  millions  of  indi- 
viduals, constituting  a  "  plaque,"  and 
attaching  or  agglutinating  themselves  to 
the  tooth  surface,  with  the  result  that 
the  tooth  surface  to  which  they  are 
attached  undergoes  disintegration  on 
account  of  their  presence;  just  as  we 
shall  find  if  we  detach  the  moss  from  the 
ledge  that  there  are  visible  evidences  of 
some  disintegration  of  the  rock  surface 
on  account  of  its  having  contributed 
to  the  support  of  the  moss.  It  is  an 
illustration  of  th&  great  fact  that  it  is 
impossible  to  get  something  out  of  noth- 
ing. 

This  analogy  between  the  moss  on  the 
rock  and  the  bacterial  plaque  on  the 
tooth  should  be  studied  a  little  further. 
It  is  an  old  saying  that  "  A  rolling  stone 
gathers  no  moss."  This  is  rightly  taken 
to  be  an  impressive,  emphasized  state- 
ment of  figurative  truth,  through  the 
assertion  of  a  physical  fact  so  patent  that 

31 


HARVARD  HEALTH  TALKS 

no  one  could  think  of  disputing  it.  The 
impacts  and  friction  to  which  the  rolling 
stone  is  subject  keep  it  free  from  attach- 
ments of  parasitic  life,  —  keep  its  surface 
clean.  Almost  as  positively  as  this,  we 
can  say  that  the  tooth  surface  which  is 
habitually  well  frictionized  will  be  kept 
clear  of  adhesions  of  mischief -making  mi- 
croorganisms, and  will  not  suffer  from 
disintegration  and  decay.  Indeed  the 
rule  applies  more  emphatically  to  the 
tooth  than  to  the  stone,  because  in  the 
tooth  the  friction  acts  as  a  stimulation 
to  the  natural  constructive  powers  to  in- 
crease the  strength  of  the  resistance,  and 
dead  stone  has  no  such  powers.  I  shall 
revert  to  this  matter  later.  Putting  the 
teeth  to  real  service  in  chewing  food  that 
requires  earnest  mastication,  their  proper 
function,  is  markedly  for  their  advantage. 
Disuse,  or  little  use,  invites  disease. 

These  things  have  been  rehearsed  in 
order  to  help  in  understanding  what  are 


CARE   OF  THE  TEETH 

the  disintegrative  influences  upon  teeth 
in  the  mouth. 

Having  before  us  these  matters  of 
tooth  constitution,  of  the  chemical 
nature  of  the  teeth,  of  existing  imper- 
fection in  the  formation  of  the  teeth,  of 
the  presence  in  the  mouth  of  various 
fermentable  substances,  and  also  of  the 
existence  there  of  millions  of  micro- 
organisms capable  of  inducing  fermenta- 
tion, we  have  a  grasp  of  a  large  part  of 
the  causation  of  tooth  decay. 

The  assertion  may  be  made  that  a 
clean  tooth  never  decays;  and  this  comes 
very  near  being  strictly  true.  So  far  as 
comes  to  my  mind  it  is  completely  and 
positively  true,  if  we  explain  that  by  a 
clean  tooth,  we  mean  one  that  is  materi- 
ally, physically,  chemically,  and  bacteri- 
ologically  clean.  Compliance  with  these 
conditions  should  eliminate  dental  caries. 

Now  we  turn  aside  for  a  moment  to 
make  a  division  into  two  classes  of  all  cav- 
ities occurring  in  teeth.     You  remember 

33 


HARVARD   HEALTH  TALKS 

what  I  said  about  imperfections  in  the 
formation  of  the  enamel  of  the  teeth, 
—  the  pits  and  fissures  and  seams  and 
imperfect  \  places  in  the  teeth,  which 
make  interruptions  in  the  continuity  of 
the  enamel  sheet.  When  I  was  speaking 
of  such  things,  I  might  have  stated  that 
illness,  particularly  of  the  exanthema- 
tous  type,  occurring  in  young  children 
at  the  period  in  their  life  history  when 
the  teeth  are  undergoing  the  process  of 
calcifying,  often  leaves  its  marks  in  the 
shape  of  grooves  or  a  row  of  pits  trans- 
versely upon  the  teeth,  occasioned  by 
nature's  modified  capacity  for  construc- 
tion during  the  illness.  These  are  com- 
parable to  the  marks  of  imperfection  in 
the  formation  of  the  finger  nails,  often 
apparent  after  severe  illnesses  in  adults. 
It  is  like  the  flaw  in  the  weaver's  web  if 
the  shuttle  does  not  pass  as  it  should  as 
the  web  is  being  advanced  in  the  loom. 
We  make  our  first  great  group  of  cavities 
in  the  teeth  include  those  cavities  which 

34 


CARE  OF  THE  TEETH 

have  their  initiation  in  the  fissures  of 
original  imperfect  formation.  They  come 
very  largely  upon  what  are  called  the 
grinding  surfaces  of  the  molars  and  in 
the  valleys  of  the  bicuspids.  Here  the 
process  of  decay  is  invited  and  facilitated 
in  ways  which  we  are  about  to  see.  We 
put  in  our  second  group  of  cavities  those 
which  are  formed  upon  surfaces  of  teeth 
where  the  original  construction  involved 
no  imperfection.  In  this  second  class  of 
cavities,  we  shall  find  almost  invariably 
a  disadvantage  of  environment  which 
made  the  attainment  of  any  good  degree 
of  cleanliness  a  much  more  difficult  thing 
than  in  the  case  of  surfaces  that  are 
freely  exposed  to  friction.  Practically 
speaking  a  tooth  surface  receiving  from 
mastication  or  any  other  circumstance  a 
good  deal  of  friction  is  thereby  exempted 
from  an  attack  of  caries. 

Now,  bearing  in  mind  these  circum- 
stances of  unfavorable  environment,  of 
untidiness,    of   accumulation   of    debris 

35 


HARVARD   HEALTH  TALKS 

of  food,  of  oral  fluids  little  moved  or 
changed  and  really  stagnated,  we  are 
prepared  to  come  back  to  our  theory  of 
causation  of  disintegration  of  teeth  by 
decay. 

This  debris  accumulated  around  the 
teeth  is  acceptable  and  congenial  pabu- 
lum for  multitudes  of  microorganisms 
which  flourish  there,  and  as  a  result  of 
their  life  history  produce  acids.  Just  as 
we  have  seen  the  souring  of  milk  from 
the  presence  of  an  acid-producing  micro- 
organism, we  may  see  a  like  process  tak- 
ing place  in  the  mouth  with  like  results; 
and  the  acid  thus  formed  directly  upon 
those  surfaces  of  the  teeth  less  exposed 
to  friction  begins  a  process  of  disintegra- 
tion of  enamel  which  is  the  first  step  in 
the  formation  of  cavities  which  come 
upon  tooth  surfaces  where  there  was  no 
original  defective  formation.  This  means 
that  cavities  of  what  we  are  calling  the 
second  class  come  in  between  the  teeth 
especially  if  there  are  places  in  which 

36 


CARE   OF  THE  TEETH 

food  habitually  lodges  and  is  permitted 
to  remain.  Such  cavities  come  also  at 
the  necks  of  teeth,  at  the  margin  of  the 
gums,  if  there  is  not  tidiness  and  care  in 
the  removal  of  the  remains  of  food.  They 
are  especially  likely  to  come  about  the 
third  molar  or  wisdom  tooth  on  account 
of  the  general  unf avorableness  of  the  en- 
vironment. Often  these  teeth  are  not 
fully  erupted.  They  may  remain  for 
years  only  partially  through,  not  yet  oc- 
cupying their  right  places,  with  possibly 
a  flap  of  the  gum  partially  overlapping 
them  and  making  a  pocket  for  the  reten- 
tion of  particles  of  fflod  and  other  debris. 
The  cheek  often  lies  in  close  apposition 
with  the  surface  of  the  tooth,  and  in  all 
particulars  the  environment  is  most  un- 
favorable. To  this  is  often  added  ineffi- 
ciency in  the  means  of  cleaning,  when 
the  tooth  brush  is  not  made  to  reach  so 
far  back  as  these  teeth.  This  is  very 
largely  the  explanation  of  the  popular 
idea  that  the  wisdom  tooth  is  the  poor- 

37 


HARVARD  HEALTH  TALKS 

est  tooth  in  the  mouth.  As  a  matter  of 
fact,  being  formed  last,  when  the  tooth- 
building  powers  of  the  system  are  at 
their  best,  the  wisdom  tooth  is  frequently 
very  well  constituted ;  but  it  is  the  unfor- 
tunate victim  of  its  surroundings.  In 
numerous  instances  it  is  more  sinned 
against  than  sinning. 

After  the  action  of  the  product  of  mi- 
croorganisms, and  note  that  I  say  the 
action  of  the  product  of  microorganisms, 
because  no  microorganism  in  itself  has 
any  capacity  to  attack  and  disintegrate 
tooth  substance,  and  remembering  the 
physical  and  chemical  make-up  of 
enamel  and  dentine,  we  are  prepared  to 
see  that  the  conjoined  action  of  micro- 
organisms and  acid  constitute  the  active 
agencies  in  the  production  of  decay.  As 
a  matter  of  fact,  no  microorganism  is  so 
small  as  to  be  able  to  penetrate  into  the 
sound  dentine.  They  are  all  too  large 
to  be  accommodated  within  the  diameter 
of  the  dentinal  tubule.    When  the  den- 


CARE  OF  THE  TEETH 

tine  has  undergone  softening  by  the  acid 
action,  the  microorganisms  are  able  to 
penetrate  the  tubules,  and  do  penetrate 
them  and  carry  on  the  process  of  fer- 
mentation with  the  result  of  acid  forma- 
tion in  the  cavity  of  decay.  Thus  it  is 
that  the  more  organisms,  the  more  for- 
mation of  acid,  the  more  acid  formation, 
the  more  disintegration  of  lime  salts,  the 
more  softening  of  the  dentinal  tubules, 
the  more  penetration  of  organisms  with- 
in the  tubules,  all  together  pushing  on 
the  process  of  disintegration  and  decay. 

Now,  leaving  this,  let  us  consider  the 
other  great  class  of  oral  diseases  whose 
action  occasions  the  loss  of  many  good 
teeth,  namely,  disease  of  the  investments 
of  the  teeth,  disease  of  the  gums,  disease 
of  the  bony  sockets  of  the  teeth.  This  is 
often  spoken  of  as  recession  of  the  gums, 
spongy  gums,  elongation  of  the  teeth, 
loosening  of  the  teeth,  or  by  other  such 
names.      There    are    various    popular 


HARVARD  HEALTH  TALKS 

names  for  it,  and  various  other  names 
used  by  dentists.  A  designation  a  good 
deal  used  is  "  Riggs'  disease."  This 
term  is  in  recognition  of  the  part  which 
the  late  Dr.  John  M.  Riggs,  of  Hart- 
ford, took  about  forty -five  years  ago  in 
pointing  out  a  considerable  share  of  its 
true  pathology.  It  is  called  by  dentists 
pyorrhoea  alveolaris,  which  means  liter- 
ally, a  flow  of  pus  from  the  alveolus, 
that  is,  from  the  tooth  socket.  It  is 
spoken  of  sometimes  as  interstitial  gingi- 
vitis, which  signifies  inflammation  within 
the  substance  of  the  gums,  sometimes  as 
phagedenic  percementitis,  which  means  a 
wasting  inflammation  about  the  roots. 
It  is  an  affection  whose  causation,  al- 
though partially  understood  for  a  good 
many  years,  has  not  been  thoroughly 
comprehended  until  very  recently;  and 
it  is  no  doubt  true  that  we  have  not  yet 
come  to  understand  all  that  is  to  be 
learned  and  that  we  ought  to  know  about 
this  disease. 

40 


CARE  OF  THE   TEETH 

Dr.  Riggs'  own  theory  of  it  was  that 
it  was  very  largely  due  to  accumulations 
of  foreign  substances,  such  as  are  popu- 
larly spoken  of  as  tartar,  about  the  teeth. 
This  formation  is  ordinarily  greatest 
upon  those  tooth  surfaces  situated  oppo- 
site to  the  openings  of  the  ducts  which 
bring  saliva  into  the  mouth,  or  in  other 
words  upon  the  lingual  aspect  of  the 
lower  front  teeth  and  the  buccal  side  of 
the  upper  molars. 

The  saliva  may  hold  in  suspension 
salts  of  lime  chemically  resembling  the 
salts  of  lime  which  constitute  a  large 
part  of  the  teeth.  These  salts  are  likely 
to  be  deposited  upon  any  hard  stationary 
surface  which  may  be  in  their  way.  The 
deposit  of  tartar  ordinarily  begins  at  the 
margin  of  the  gum  in  positions  not  well 
exposed  to  friction,  and  gradually  in- 
creases, extending  itself  upon  the  exposed 
portion  of  the  crown  of  the  tooth  and 
insinuating  itself  under  the  margin  of 
the  gum  upon  the  root,  occasioning  irri- 

41 


HARVARD  HEALTH  TALKS 

tation  and  extending  farther  and  farther, 
until  it  loosens  the  attachment  of  the 
gum  to  the  tooth,  induces  a  marked 
congestion  and  chronic  inflammation  of 
the  soft  tissues  with  morbific  discharges, 
including,  in  deep-seated  cases,  the  con- 
stant production  of  pus.  There  also 
appears  in  these  deep-seated  cases  some 
loss  of  vitality  of  the  thin  margin  of  the 
bony  socket  of  the  tooth,  the  alveolus; 
and  this  may  progress  in  connection  with 
the  other  recession  and  may  go  on  until 
nearly  or  quite  all  of  the  socket  has 
vanished.  The  tooth  becomes  extremely 
loose,  and  either  falls  out  of  itself,  or 
becomes  so  troublesome  that  it  is  pur- 
posely removed. 

It  has  been  the  theory  of  our  English 
professional  friends  that  in  this  disease, 
the  primary  disturbance  was  in  the  bony 
tissue  of  the  margin  of  the  socket;  and 
that  the  other  manifestations,  including 
the  deposit  of  calculus,  were  to  be  classed 
among  consequences  rather  than  causes 

42 


CARE  OF  THE  TEETH 

of  the  disease.  I  have  no  doubt  that 
there  is  a  very  small  percentage  of  cases 
in  which  this  is  true,  cases  of  caries  and 
necrosis  of  bone  and  of  mercurialization ; 
but  the  general  truth  of  our  own  ideas 
about  it  appears  to  be  supported  by  the 
undenied  fact  that,  practically  speaking, 
the  disease  always  vanishes  promptly 
when  the  teeth  with  their  attached  de- 
posits are  removed. 

Another  theory  with  reference  to  the 
cause  of  this  affection  is  the  microorganic 
theory.  Without  any  manner  of  doubt, 
there  are  numerous  cases  in  which  micro- 
organisms do  have  a  part  in  carrying  for- 
ward the  affection.  This  would  seem  to 
be  proved  by  the  fact  that  in  numbers 
of  cases  the  use  of  autogenous  vaccines 
prepared  from  cultures  from  the  indi- 
vidual mouths,  or  even  stock  vaccines 
of  microorganisms  of  types  having  much 
to  do  in  causing  suppuration,  is  often 
followed  by  most  gratifying  results  in 
mitigating,  if  not  curing,  the  disease. 

43 


HARVARD  HEALTH  TALKS 

Very  recent  discoveries  appear  to  show 
in  a  large  proportion  of  these  cases  the 
presence  of  pus-producing  parasites, 
animal  in  their  nature,  which  may  be 
killed  by  a  specific  germicide.  From 
limited  experience  the  claim  is  made  that 
this  treatment  in  connection  with  the 
proper  instrumentation  goes  far  toward 
relieving  the  trouble. 

Another  causative  factor  in  this  affec- 
tion is  believed  to  be  inefficiency,  incom- 
pleteness or  tardiness  in  the  elimination 
of  waste  products,  especially  through 
the  alimentary  canal,  and  the  kidneys. 
Habitual  costiveness,  the  undue  reten- 
tion within  the  system  of  waste  material 
which  should  have  been  rejected,  with- 
out doubt  leads  in  some  cases  to  a  vi- 
carious elimination  in  which  the  mouth 
suffers.  A  similar  statement  may  be 
made  about  the  failure  of  the  kidneys 
to  carry  out  of  the  system  those  wastes 
which  it  is  their  proper  function  to 
excrete. 

44 


CARE   OF  THE  TEETH 

One  thing  that  is  absolutely  sure 
about  this  disease  when  it  has  once  be- 
come deeply  established  is  that  it  can 
never  cure  itself  or  come  to  an  end  spon- 
taneously, with  anything  short  of  the 
loss  of  the  teeth.  Another  sure  thing 
is  that  in  any  treatment  of  the  trouble 
which,  the  dentist  institutes  there  can  be 
no  real  success  unless  that  treatment  in- 
cludes the  thorough  removal  of  all  con- 
cretions from  the  surfaces  of  the  teeth, 
and  especially  and  emphatically  from 
those  surfaces  of  the  teeth  that  are  be- 
neath the  gum. 

There  are  most  important  relation- 
ships between  tfhese  mouth  diseases  and 
systemic  diseases  of  a  variety  of  types. 
In  many  cases  the  mouth  disease  stands 
in  a  causative  relation  to  the  other  dis- 
ease; but  those  are  things  which  we  can- 
not include  in  this  study  now. 

One  other  general  fact  should  be 
brought  into  the  reckoning;  and  that  is 
that  the  habitual  chemical  quality  of  the 

45 


HARVARD   HEALTH  TALKS 

oral  fluids  has  a  good  deal  to  do  with  this 
matter  of  caries  and  also  of  deposits  upon 
the  teeth.  It  is  believed  that  the  chem- 
ical condition  of  the  oral  fluids  is  in- 
tended to  be  slightly  alkaline.  It  should 
at  least  be  neutral.  If  it  is  slightly  alka- 
line there  are  therein  advantages.  One 
of  these  is  that  the  food  in  the  process 
of  mastication  and  insalivation  is  satu- 
rated with  a  fluid  somewhat  alkaline  and 
is  thereby  the  better  prepared  for  stom- 
ach digestion,  a  process  carried  on  largely 
by  the  gastric  juice,  which  has  marked 
acidity  as  one  of  its  characteristics.  A 
further  advantage,  and  one  of  great 
practical  consequence  in  connection  with 
our  present  study,  is  that  this  alkalinity 
gives  protection  for  the  teeth  from  the 
action  of  acids  to  which  they  are  fre- 
quently exposed,  such  as,  for  instance, 
the  acids  of  condiments  and  of  many 
fruits,  like  apples,  peaches,  oranges, 
grapes,  strawberries,  etc.  Whenever 
there  is  produced  by  these  things  the 

4G 


CARE  OF  THE  TEETH 

sensation  of  the  teeth  being  "  set  on 
edge  "  the  explanation  lies  in  the  super- 
ficial corrosion  and  irritation  by  the 
acid. 

The  dentist  often  sees,  particularly  in 
the  case  of  young  girls  who  are  not  fully 
developed,  and  are  perhaps  overworking 
in  school,  or  combining  with  their  work 
too  great  devotion  to  society,  with  late 
hours,  and  making  various  mischievous 
inclusions  in  their  diet,  mouths  that 
show  unmistakably  the  habitual  pres- 
ence of  acidity.  Associated  with  that 
acidity  are  almost  inevitably  to  be 
found  the  ravages  of  extensive  decay, 
extreme  sensitiveness,  and  an  entire 
absence  of  calcareous  deposits  or  tartar. 
In  such  a  case  more  can  be  done  for 
the  well-being  of  the  teeth  by  elimi- 
nating the  unhygienic  factors  in  the 
patient's  life  and  by  building  up  the 
general  health,  getting  nature's  functions 
established,  maintaining  a  proper  regi- 
men in  all  particulars,  and  especially  by 

47 


HARVARD  HEALTH  TALKS 

antagonizing  the  acid  condition,  than 
can  possibly  be  accomplished  by  the 
dentist  in  his  operations  of  filling  cavi- 
ties alone. 

More  rarely  there  may  be  such  ex- 
treme alkalinity  of  the  oral  fluids,  such 
a  superabundance  of  lime  salts  held 
in  suspension,  that  there  become  at- 
tached to  the  teeth  great  quantities  of 
calcic  concretions  from  which  it  is  ex- 
tremely difficult  to  keep  them  free. 
These  are  in  no  way  a  menace  to  the 
tooth  structure  itself.  They  do  not 
cause  decay;  but  their  influence  is  likely 
to  be  in  the  direction  of  causing  Riggs' 
disease.  In  antagonizing  hyperalkalin- 
ity  we  do  not  know  how  to  do  directly 
and  safely  very  much  with  chemical 
agents,  for  the  reason  that  the  constitu- 
tion of  calcareous  concretions  is  chemi- 
cally so  similar  to  the  constitution  of  the 
teeth  themselves  that  whatever  is  cap- 
able of  attacking  one  is  likely  to  attack 
the  other. 

48 


CARE  OF  THE  TEETH 

Now,  without  following  this  any  fur- 
ther, we  have  compassed,  I  am  sure,  an 
understanding  of  what  agencies  are  very 
powerful  workers  against  the  well-being 
of  the  teeth,  and  have  had  at  least  sug- 
gestions as  to  what  are  helpful  measures 
to  use  in  their  preservation. 

All  of  these  considerations  point  to  the 
fact  that  the  intelligent  use  of  agencies 
for  maintaining  a  good  degree  of  cleanli- 
ness of  the  teeth  is  of  great  consequence 
in  attaining  freedom  from  disease,  and 
in  antagonizing  th£  influences  that  tend 
to  the  disintegration  and  loss  of  the 
teeth.  The  faithful  and  intelligent  use 
of  a  brush  of  proper  quality,  not  too 
hard  and  not  too  soft,  supplemented  by 
such  dentifrices  and  mouth  washes  as 
may  be  useful  in  particular  cases  (not 
the  same  for  all  people),  with  the  use  of 
silk  drawn  between  the  teeth  to  cleanse 
the  surfaces  most  in  need  of  cleaning  and 
most  susceptible  to  decay,  are  our  main 

49 


HARVARD  HEALTH  TALKS 

reliances.  When  conveniently  possible 
they  should  be  used  after  eating,  parti- 
cularly after  the  last  meal  of  the  day. 
The  most  important  time  is  before  re- 
tiring at  night.  If  the  teeth  may  not  be 
brushed  after  some  of  the  meals  the 
thorough  rinsing  of  the  mouth  may  be 
helpful. 

To  this  care  should  be  added,  of 
course,  if  needed,  the  counteracting  or 
antagonizing,  or  better  still,  the  preven- 
tion of  acid  conditions. 

In  the  antagonizing  of  acid  we  have 
four  principal  agents,  all  of  which  are 
useful  in  various  degrees.  The  first  of 
these  is  prepared  chalk  which  chemically 
neutralizes  acid.  It  constitutes  the  basis 
of  most  of  the  good  dentifrices.  A  sec- 
ond means  of  locally  antagonizing  acid 
in  the  mouth  is  bicarbonate  of  soda. 
There  are  some  objections  alleged  to  the 
use  of  this  remedy;  but  I  believe  that 
they  are  theoretical  rather  than  prac- 
tical.    As  much  sodium  bicarbonate  as 

50 


CARE  OF  THE  TEETH 

can  be  held  upon  a  dime,  dissolved  in  a 
small  glass  of  warm  water  and  used  in 
rinsing  the  mouth,  is  one  of  the  helps 
in  antagonizing  acidity.  Another  good 
antacid  is  lime  water.  Lime  is  soluble  in 
water  only  to  a  very  slight  extent;  and 
it  may  be  very  conveniently  prepared 
for  use  by  first  satisfying  its  affinity  for 
water,  or  in  other  words  slaking  it.  For 
this  there  should  be  used  a  clean  piece 
of  board,  or  something  which  will  not 
be  broken  by  the  sudden  development 
of  heat  when  the  lime  and  water  are 
brought  together.  Put  the  mixture  in  a 
bottle,  and  fill  with  water,  and  you  will 
always  have  conveniently  at  hand  a  sat- 
urated solution  of  lime.  This  may  be 
diluted  somewhat  with  plain  water,  but 
ordinarily  need  not  be  much  diluted.  If 
made  not  disagreeably  strong,  it  may  be 
used  freely  as  a  mouth  wash.  It  may  also 
be  used  advantageously  as  an  addition 
to  milk,  to  facilitate  its  digestibility  and 


51 


HARVARD  HEALTH  TALKS 

avoid  curds  in  the  stomach  and  prevent 
gastric  acidity. 

A  fourth  and  most  effective  agency 
for  antagonizing  acidity  is  milk  of  mag- 
nesia. This  is  not  a  thing  to  be  used  in 
brushing  and  cleaning  the  teeth;  but  its 
use  should  follow  the  cleaning  agencies, 
particularly  at  night,  by  taking  a  small 
teaspoonf  ul  of  the  milk  of  magnesia  into 
the  mouth,  and  with  the  tongue  and 
cheeks  smearing  it  over  the  teeth.  In 
this  way  its  influence  is  very  persistent 
and  efficient. 

The  teeth  ordinarily  decay  more  dur- 
ing the  quiescence  of  the  mouth  at  night 
than  they  do  during  the  day;  and  this 
use  of  magnesia  brings  the  helpful  agency 
into  service  at  the  time  when  it  can  do 
the  most  good. 

To  speak  a  little  more  about  dentifrices 
—  they  are  almost  without  exception  in- 
nocent and  more  or  less  effective.  Some 
are  much  better  than  others;  but  there 

52 


CARE  OF  THE  TEETH 

is  little  occasion  for  incorporating  in 
them  anything  injurious;  and  those  that 
are  produced  and  sold  by  reputable  phar- 
macists are  almost  invariably  free  from 
any  harmful  quality.  The  street  fakir 
who  works  a  transformation  from  the 
unsightliness  of  the  teeth  of  the  gamin 
probably  uses  a  preparation  containing 
alum  or  some  kind  of  acid;  but  such 
agencies  are  not  likely  to  be  used  by  in- 
telligent people.  Some  of  the  newer 
proprietary  preparations  whose  well 
chosen  ingredients  are  declared,  so  com- 
bine germicidal  influence  with  the  right 
abrasive  quality  atid  a  capacity  for  an- 
tagonizing acids  as  to  make  them  supe- 
rior preparations.  I  suppose  that  in  this 
place  I  ought  not  to  make  mention  of 
any  particular  preparation;  but  I  have 
confidence  in  the  general  beneficial  in- 
fluence of  the  better  specimens  of  the 
class  that  I  have  in  mind,  not  only  for 
their  good  effect  upon  the  teeth,  but  as 
having  much  influence  in  lessening  the 

53 


HARVARD  HEALTH   TALKS 

pathogenic  microorganisms  of  the  mouth 
and  throat,  and  so  contributing  mate- 
rially to  the  user's  well-being  in  other 
ways.  Special  dentifrices  and  mouth 
washes  for  individual  needs  should  be 
prescribed  or  provided  by  the  dentist. 

The  manner  of  using  the  brush  in 
order  that  good  and  not  harm  may  result 
should  be  mentioned.  Occasionally  a 
person  with  more  zeal  than  discretion, 
using  a  stiff  brush  and  a  coarse  powder 
with  a  crosswise  motion  of  the  brush 
over  the  necks  of  the  teeth,  does  make 
mischief.  The  margin  of  the  gum  is 
fretted  and  forced  back,  the  softer  por- 
tion of  the  tooth  above  or  below  the 
enamel  border  is  exposed,  and  may  be 
materially  worn  so  as  to  constitute  a 
V-shaped  groove,  markedly  for  the 
tooth's  disadvantage.  The  right  way 
to  use  the  brush  is  to  place  it  upon  the 
gum  and  with  a  half -rotary  motion  bring 
it  perpendicularly  upward  upon  the  lower 
teeth,  downward  on  the  upper  teeth,  in 

54 


CARE   OF  THE  TEETH 

such  a  way  as  to  avoid  this  danger  of 
mischief  which  has  just  been  described 
as  possible  in  the  crosswise  motion.  With 
this  motion  of  the  brush,  not  only  is  no 
harm  likely  to  come  to  the  soft  tissues, 
but  the  cleansing  of  the  teeth  will  be 
much  more  efficient  through  the  passing 
of  the  bristles  of  the  rightly  trimmed 
toothbrush  between  the  teeth,  than 
could  possibly  be  the  case  if  the  crosswise 
motion  were  used.  The  bristles  of  the 
brush  should  not  be  set  together  too 
compactly,  and  they  may  well  be 
trimmed  so  as  to  give  the  brush  a  ser- 
rated face.  m 

Of  course,  when  we  are  considering  the 
means  of  preserving  the  natural  teeth 
we  have  to  include  the  dentist's  services. 
In  the  arrest  of  dental  decay  by  the  pro- 
cess of  rilling,  in  antagonizing  disease  of 
the  investments  of  the  teeth  through  the 
removal  of  foreign  deposits,  and  in  the 
treatment  of  numerous  pathological  con- 

55 


HARVARD  HEALTH  TALKS 

ditions  as  they  arise  in  and  about  the 
teeth  and  mouth  the  dentist's  services 
are  for  the  average  individual  absolutely 
indispensable.  No  class  of  men  would 
be  more  glad  to  have  teeth  cease  to  need 
repairing  than  would  dentists,  just  as 
no  other  class  of  men  would  be  so  glad 
to  have  humanity  cease  to  suffer  from 
general  diseases  as  would  physicians. 
And  there  is  a  way  of  practicing  den- 
tistry which  is  capable,  and  has  been 
proved  to  be  capable,  of  setting  aside  a 
large  part  of  the  ills  to  which  teeth  are 
heir.  This  is  a  system  which  is  spoken 
of  as  prophylaxis,  which  comes  from  a 
Greek  word  which  signifies  prevention. 
We  are  told  that  in  China  there  is  a 
practice  of  medicine  through  which  the 
patient  pays  to  his  medical  adviser  a  sal- 
ary, and  this  salary  goes  on  so  long  as 
the  patient  remains  well.  The  instant 
the  patient  becomes  ill  the  salary  stops 
and  stays  stopped  until  the  patient  is  re- 
stored to  health.     Dental  prophylaxis 

56 


CARE  OF  THE  TEETH 

has  resemblance  to  this.  The  dentist 
is  paid  for  preventing  dental  caries  and 
pyorrhoea  alveolaris,  not  for  repairing 
or  attempting  to  repair  the  mischief  after 
it  has  been  done.  As  sometimes  pursued, 
this  system  gives  the  dentist  an  annual 
salary.  The  dentist  on  his  part,  insists 
on  having  an  opportunity  to  give  the 
teeth  a  thorough  cleansing  and  scrubbing 
once  a  month  regularly.  This  process 
commenced  in  children  and  persistently 
followed  up,  aided  by  the  intelligent 
cooperation  of  the  patients  in  maintain- 
ing cleanliness,  does  result  in  the  preven- 
tion of  a  very  large  number  of  decay 
cavities  of  our  second  class,  those  upon 
the  surfaces  where  there  was  originally 
perfection  of  formation.  You  will  be 
the  better  prepared  to  believe  this  by 
going  back  to  the  fact,  stated  earlier, 
that  the  teeth  are  in  a  sense  modified 
dermal  structures,  with  many  of  the 
characteristics  of  such  structures.  One 
of  these  characteristics  of  especial  conse- 

57 


HARVARD  HEALTH  TALKS 

quence  in  the  present  connection  is  the 
effect  of  friction,  of  a  good  deal  of  fric- 
tion often  repeated.  When  this  comes 
upon  the  skin  it  induces  a  thickening 
and  hardening,  intended  by  nature  for 
self-defence,  like  the  callosity  in  the 
hand  of  the  man  who  does  rough  work, 
and  the  thickening  of  the  skin  on  the 
bottom  of  the  feet. 

If  the  dentist  has  the  opportunity  to 
begin  the  application  of  this  system  with 
a  stick  and  pumice  stone  on  all  of  the 
tooth  surfaces  of  a  young  child,  and 
keeps  up  this  process  faithfully,  there  is 
developed  in  the  tooth  tissue,  greatly 
increased  hardness  and  resistive  capac- 
ity. Were  people  to  adopt  this  system, 
and  were  the  cavities  consequent  upon 
imperfection  in  formation  cut  out  and 
filled  early  there  would  be  practically 
almost  no  more  occasion  for  filling  of 
teeth.  Pyorrhoeal  conditions  would  be 
altogether  prevented,  and  there  would  be 
maintained  constantly  a  dental  and  oral 

58 


CARE  OF  THE  TEETH 

health  beautiful  to  see  and  delightful  to 
experience.  The  visit  to  the  dentist 
would  lose  its  terrors;  and  the  patient 
would  go  to  the  dental  office  with  the 
same  equanimity  as  if  the  visit  were  a 
visit  to  the  manicure. 

The  other  things  which  I  wish  to  say 
have  regard  to  popular  ideas  more  or 
less  generally  held.  One  of  these  is  that 
sweet  things  occasion  a  great  deal  of 
trouble  with  teeth.  This  is  very  largely 
an  error.  Sugar,  so  long  as  it  remains 
sugar,  is  absolutely  incapable  of  harm- 
fully influencing  sound  tooth  tissue. 
When  not  taken  in  excess  and  at  unsuit- 
able times  and  if  taken  in  a  way  so  as 
to  form  legitimately  a  part  of  the  diet 
to  be  digested  with  other  food,  sugar 
is  not  only  harmless,  but  provides  ma- 
terial needed  for  the  nutrition  of  the 
body  and  the  maintenance  of  its  temper- 
ature. The  mischief  from  sweets  comes 
through  their  supplying  a  substance  that 

59 


HARVARD  HEALTH  TALKS 

is  capable  of  comparatively  ready  fer- 
mentation in  the  mouth  and  in  the 
stomach.  They  may  be  taken  in  such 
quantities  as  to  impair  the  digestion, 
and  to  lead  to  a  decided  acidity  which, 
if  not  directly  developed  in  the  mouth, 
is  conveyed  from  the  stomach  to  the 
marked  disadvantage  of  the  teeth.  But 
the  accusation  which  dentists  very  fre- 
quently hear  parents  bring  against  chil- 
dren, that  the  decay  of  their  teeth,  and 
their  toothaches  are  due  to  the  use  of 
sweets,  is  in  most  instances  injustice. 

Another  idea  is  that  the  period  of 
gestation  and  lactation  in  women  is  a 
time  fraught  with  peculiar  danger  to  the 
teeth.  The  popular  idea,  popularly  ex- 
pressed, is  that  "  every  child  costs  its 
mother  a  tooth."  There  is  some  founda- 
tion for  this  belief.  The  explanation  is 
partly  in  the  extra  demand  upon  the 
mother's  system  in  the  nourishment  of 
the  new  being  during  the  pregnancy; 
but  probably  to  a  greater  extent  the 

60 


CARE  OF  THE  TEETH 

harm  to  the  teeth  comes  as  a  conse- 
quence of  the  derangement  of  the 
mother's  system.  Not  rarely  during 
pregnancy  there  is  disturbance  of  di- 
gestion as  manifest  in  the  morning  sick- 
ness. The  vomiting  of  pregnancy  has 
associated  with  it  marked  acidity.  This 
prevailing  acidity  is  largely  the  explana- 
tion of  the  lesions  which  take  place  in 
teeth  during  gestation.  In  the  light  of 
all  of  the  facts  presented,  there  appears 
the  logical  deduction  that  at  this  period 
there  should  be  especial  care  in  the  use 
of  means  to  antagonize  acid  conditions. 
Another  idea^which  dentists  hear  ex- 
pressed almost  constantly  is  that  medi- 
cines are  great  mischief-makers  for  teeth. 
"  I  always  had  good  teeth  until  I  had  a 
fit  of  sickness,  and  then  the  doctors  gave 
me  so  many  medicines  that  my  teeth 
were  ruined."  This  is  usually  rank  in- 
justice to  the  physician;  and  the  dentist 
should  be  earnest  in  correcting  the  pa- 
tient's erroneous  beliefs.    Ordinarily  the 

61 


HARVARD   HEALTH  TALKS 

troubles  with  the  teeth  are  due  to  the  ill- 
ness and  conditions  associated  with  the 
illness,  and  not  to  the  medicines.  Almost 
all  medicines  as  now  used  are  harmless 
to  teeth;  but  there  are  a  few  that  may 
injure  teeth  or  their  investments.  When 
one  has  included  acids,  salts  from  which 
acids  may  be  liberated,  some  of  the  iron 
preparations  and  the  mercurials,  the  lat- 
ter particularly  when  pushed  to  the  ex- 
tent of  producing  salivation,  the  list  is 
nearly  complete. 

There  are  cases,  particularly  of  children, 
in  which  it  is  desirable  to  provide  the  sys- 
tem with  special  nutrition  for  the  teeth. 
An  established  fact  in  this  connection  is 
that  if  lime  salts  are  to  be  supplied  in 
the  diet  for  the  good  development  of  the 
teeth  and  the  bones,  they  should  be  the 
lime  salts  which  are  prepared  by  nature 
rather  than  in  the  chemist's  laboratory. 
Synthetically  produced  lime  salts  are  not 
assimilated  and  appropriated  into  the 


CARE  OF  THE  TEETH 

body;  they  pass  out  very  largely  as  they 
entered;  but  the  lime  salts  which  nature 
produces,  the  lime  salts  in  eggs,  in  meat, 
in  milk  and  in  cereals,  are  in  the  shape 
that  nature  can  assimilate,  and  appro- 
priate to  the  nutrition  of  the  tissues 
which  are  formed  of  such  materials.  If 
we  are  to  administer  special  lime  salts 
it  is  believed  that  the  lactophosphate, 
really  prepared  from  milk,  is  among  the 
most  advantageous. 

The  maintenance  of  good  systemic 
health,  good  digestion,  good  assimila- 
tion, good  nutrition,  good  elimination  of 
waste,  the  proper  performance  of  func- 
tion generally,  has  much  to  do  with  the 
health  of  the  mouth  and  exemption  from 
dental  and  oral  diseases. 


63 


PRINTED  AT 

THE  HARVARD  UNIVERSITY  PRESS 

CAMBRIDGE,  MASS.,  U.S.A. 


COLUMBIA  UNIVERSITY  LIBRARIES  (hsl.stx) 

RK  61  B72  C.1 

The  care  of  the  teeth. 

Ill 

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